Project Summary Approximately one-third of adults in the United States have prehypertension which increases the risk of hypertension and cardiovascular disease (CVD). Early detection of prehypertension offers a window of opportunity to prevent progression to overt hypertension and CVD through behavioral modification. Sympathetic activation and arterial stiffness are both deleterious factors that concomitantly contribute to elevated blood pressure. Mindfulness-Based Stress Reduction (MBSR) programs have been shown to reduce blood pressure in prehypertensive adults, but the mechanisms for the reduction remain speculative. We will systematically examine 24-hour blood pressure regulation and two potential mechanisms for the anti- hypertensive effects of MBSR by directly assessing muscle sympathetic nerve activity (MSNA) and arterial stiffness. Aim 1 will determine if MBSR improves 24-hour blood pressure regulation, aim 2 will determine if MBSR reduces sympathetic neural activity, and aim 3 will determine if MBSR will decrease arterial stiffness in prehypertensive adults. This project will also provide advanced research opportunities to undergraduate and graduate students in health-related fields at Michigan Technological University, consistent with the goals of the Academic Research Enhancement Award (R15) mission. Our central hypothesis is that MBSR will: 1) improve nocturnal blood pressure dipping and / or reduce early-morning surges, 2) reduce resting MSNA and attenuate the neural cardiovascular responses to acute stress, and 3) decrease arterial stiffness. We will utilize a parallel, randomized, control design (MBSR vs. active control) that includes gold-standard techniques for measuring blood pressure (24-hour ambulatory assessment), MSNA (microneurography), and arterial stiffness (applanation tonometry). These studies will provide detailed insight how MBSR interventions influence neural and cardiovascular control in humans. Finally, this project would help to advance the potential for MBSR to be used for reducing the onset of hypertension and other cardiovascular risks, and findings from the proposed studies may help to direct future efficacy-related work.